As much as 10 percent of the Earth's avian species may have been lost.

Human colonization of the Pacific Islands likely caused the extinction of nearly 1,000 species of large-bodied, flightless birds known as passerine landbirds.

A study of fossils from 41 Pacific islands found that two-thirds of bird populations on these islands went extinct in the period between the first arrival of humans and European colonization, or roughly from 3,500 to 700 years ago. Overhunting by humans, exacerbated by forest clearance, was a major cause of prehistoric bird extinctions.

Extinction rates between islands varied greatly but were higher for smaller islands and those with lower rainfall, which were more extensively deforested. Larger islands experienced lower rates of extinction, partially because they would have supported larger bird populations, but also because their diverse topography would have included forests in less accessible areas, making deforestation and hunting difficult.

Species’ traits also influenced the probabilities of extinction. Large-bodied and flightless species suffered higher rates of extinction, with flightless species 33 times more likely to go extinct. These traits also made the birds easier and more profitable to hunt, and their lower rates of population growth made it harder to bounce back from overhunting or habitat loss.

Species native to archipelagos or single islands also had progressively higher extinction probabilities, about 24 times more likely than their widespread counterparts, likely due to the loss of behavioral responses to predators. In the absence of predators, birds became naive, making them tame and easy to hunt once humans arrived.

The scientists excluded New Zealand from their primary analysis of Pacific islands, due to the fact that the archipelago is well-studied and less subject to the same uncertainties as other islands.

New Zealand is the most well-documented case of how human colonization and the ensuing overhunting can devastate island bird life. The country has lost over 30 percent of its native land birds, the most notable of which is the moa, which was able to grow over over three meters tall. But that extinction rate is still relatively low by Pacific island standards. New Zealand’s large size, rugged topography, and plentiful rains set it apart from other islands in the region and have allowed species that would have otherwise gone extinct, such as the flightless kiwi and kakapo, to survive.

Extinctions of seabirds and songbirds also occurred during human colonization of the Pacific islands. The study suggests that more than 10 percent of total global bird biodiversity was lost during this extinction event, making it the largest extinction event to occur in the last 11,700 years.

Promoted Comments

Confirmation might not be glamorous, but it's is one of the keys that makes science such a powerful tool!.

Right, because if we didn't study things merely because they would be unsurprising if true, then we'd end up believing a lot of things that would be unsurprising if true, but that weren't actually true!

Or, at least, not be able to say anything better than "Well, it wouldn't be surprising if true." Which is even less glamorous than saying "Well, it wasn't a surprise, but now we know it's true."

The conclusion is obviously wrong because humans can't possibly have any affect on their environment. It was probably due to an asteroid, or volcanoes,... glaciers? um gamma ray burst or... I KNOW ... ALIENS.

Unfortunately the Kiwi and Kakapo are both close to extinction and there is an ongoing struggle to keep pest populations down here. There are no large predators that will kill wild cats, stoats or possums so it's really up to conservationists to use traps and poisons to keep these bird species around.

In terms of the Moa, they were virtually all dead by the time Europeans arrived due to the native Maori people hunting them to extinction.

It's of course not only birds. The current extinction rate (over all species) is said to be 100 to 10000 times higher than the background rate between mass extinctions. We're quite a pest for the planet it seems.

This can't be right, only modern western civilization pillages alien environments into extinction, while the natives coexist with nature in blissful harmony. Or have I interpreted the subtext of James Cameron's "Avatar" completely wrong?

This can't be right, only modern western civilization pillages alien environments into extinction, while the natives coexist with nature in blissful harmony. Or have I interpreted the subtext of James Cameron's "Avatar" completely wrong?

They may have been "native" relative to European explorers and settlers, but a lot of Pacific islands haven't been settled for long. I think the Maori only reached New Zealand 900-1300 years ago.

This can't be right, only modern western civilization pillages alien environments into extinction, while the natives coexist with nature in blissful harmony. Or have I interpreted the subtext of James Cameron's "Avatar" completely wrong?

They may have been "native" relative to European explorers and settlers, but a lot of Pacific islands haven't been settled for long. I think the Maori only reached New Zealand 900-1300 years ago.

That is correct, however there is definitely a perception that "native" peoples do live in harmony with nature when in fact they wiped out many native bird species as well as another race of humans who were here before them..

This can't be right, only modern western civilization pillages alien environments into extinction, while the natives coexist with nature in blissful harmony. Or have I interpreted the subtext of James Cameron's "Avatar" completely wrong?

They may have been "native" relative to European explorers and settlers, but a lot of Pacific islands haven't been settled for long. I think the Maori only reached New Zealand 900-1300 years ago.

That is correct, however there is definitely a perception that "native" peoples do live in harmony with nature when in fact they wiped out many native bird species as well as another race of humans who were here before them..

Bah, next you'll be telling me that the Native Americans are largely responsible for the recent extinction of most of the North American megafauna...

This can't be right, only modern western civilization pillages alien environments into extinction, while the natives coexist with nature in blissful harmony. Or have I interpreted the subtext of James Cameron's "Avatar" completely wrong?

They may have been "native" relative to European explorers and settlers, but a lot of Pacific islands haven't been settled for long. I think the Maori only reached New Zealand 900-1300 years ago.

That is correct, however there is definitely a perception that "native" peoples do live in harmony with nature when in fact they wiped out many native bird species as well as another race of humans who were here before them..

Humans are the cancer of the planet, whatever place we are living, the ecosystem is destroyed to meet our living standard or for food.

Without humans the planet, in fact the entire universe has no purpose. If we don't exist to observe the universe it ceases to exist. But, feel free to off yourself if you think it's the right thing to do, you know to slow down the "cancer".

Unfortunately the Kiwi and Kakapo are both close to extinction and there is an ongoing struggle to keep pest populations down here. There are no large predators that will kill wild cats, stoats or possums so it's really up to conservationists to use traps and poisons to keep these bird species around.

IIRC, to create a haven for the remaining Kakapo, they had to be given their own private island - one that had been painstakingly been cleared of imported predators (cats, dogs, rats, etc) almost by hand.

To be clear, moas (in the illustration) are ratites, not passerines. The dodo (although not in the Pacific) is a better example of a flightless passerine. Ratites are an ancient branch of the avian order, and have been flightless for a long time: thus they are only located on relatively large land masses that they were able to walk to in earlier eras. Passerines are a newer branch, and are usually defined as being excellent fliers: they are the ones able to reach small, remote islands. At that point some of them then specialized in island life and abandoned flight.

The conclusion is obviously wrong because humans can't possibly have any affect on their environment. It was probably due to an asteroid, or volcanoes,... glaciers? um gamma ray burst or... I KNOW ... ALIENS.

It's not unexpected, but it's still valuable knowledge. By demonstrating that the other Pacific islands show much the same extinction history as New Zealand (which has been the subject of much more study in the past), they confirm that the human extinction theory is very likely correct.

If they had found that the Pacific islands showed a different pattern, that would be cause to question the original research.

Confirmation might not be glamorous, but it's is one of the keys that makes science such a powerful tool!.

When humans looking for ways of survival, all you little things step aside. If I knew it back then that ten million year old bird worth a million dollar today I wouldn't have killed it for food. But I was hungry, what could I do then? But now you blame it on me for its distinction? Com'on!

Unfortunately the Kiwi and Kakapo are both close to extinction and there is an ongoing struggle to keep pest populations down here. There are no large predators that will kill wild cats, stoats or possums so it's really up to conservationists to use traps and poisons to keep these bird species around.

IIRC, to create a haven for the remaining Kakapo, they had to be given their own private island - one that had been painstakingly been cleared of imported predators (cats, dogs, rats, etc) almost by hand.

One thing people don't realise is that even though you might clear an island or area of predators, you continually need to monitor to ensure that these pests do not come back. rats have been known to cross bodies of water before.

Bah, next you'll be telling me that the Native Americans are largely responsible for the recent extinction of most of the North American megafauna...

Shhh... this politically incorrect info will get you nowhere.

Repeat after me: noble savages lived in harmony with the universe and in peace with each other and never wiped out the American megafauna (including killing the horse down to the very last!) nor burned the forests continent-wide.

Please give no credit to Europeans for bringing the horse back to its native land. Look, Western civilization is evil, all others are good and in harmony with Holy Gaia, mmmkay?

Alternatively, it could've been the meteorite that struck south of Stewart Island (NZ's southern-most island) in ~1440. The resulting tsunami is thought to have been 220m high and decimated many species - those flightless birds didn't stand a chance

It's not destroyed. It's converted into something useful. Our ability to perform this conversion effectively (very effectively, at that) is why humans are so awesome.

So hunting animals that we eat to extinction is making them more useful????? Tell that to the sad hunters who could never find another one after they killed them all and had to move on to not-so-easy prey. Tell that to the fishermen who seem to have a brain disease requiring them to overfish and destroy the stocks they depend on, leaving their children without jobs.

People are NOT effective at long-term planning. Short-term is all there is for the vast majority of all the humans that have ever lived. And that ain't optimal. Witness the climate-change deniers ("how dare you risk a short-term global economic recession to avert thousands of years of climate catastrophy! Think of the jobs/children").

When humans looking for ways of survival, all you little things step aside. If I knew it back then that ten million year old bird worth a million dollar today I wouldn't have killed it for food. But I was hungry, what could I do then? But now you blame it on me for its distinction? Com'on!

Allie Wilkinson / Allie is a freelance contributor to Ars Technica. She received a B.A. in Environmental Studies from Eckerd College and a Certificate in Conservation Biology from Columbia University's Earth Institute Center for Environmental Sustainability.